Is it the sbc pump or the reservoir?
 

Well, I finally got the "brake see workshop sign" in my car and assumed the worst that it was the sbc pump needing to be replaced.. and of course the 10 year unlimited mile warranty ended for me last year. I took it to a shop who hooked it up to the xentry and they told me it was just the reservoir which is a significantly cheaper part but the labor is still pretty much the same as replacing the entire sbc pump. My question is if it is wise to just opt for this repair (it is about half the price) or is it likely the pump will go shortly after. Some of the signs that appeared shortly before this warning appeared on my dash is that the break peddle became a little more soft then before and the noise the sbc pump made has become more frequent (also sounds a bit weaker at times), the last thing I noticed is a kind of loose/fluttering noise towards the front drivers side of the car when coming to complete stops (this i am not sure is related to the sbc but it began right around the same time as everything else). Any input would be appreciated.. I know this sbc pump is like a rite of passage for us benz owners of this year and make.

In case of any confusion I am talking about the hydro accumulator when I mention reservoir. The big round ball that connects to the sbc pump.

The 'feel' in the brake pedal is generated by the braking computer, so should not go soft.

So I took the car to the dealer to get a second opinion and to see if they’d honor my sbc warranty in good faith. They declined but gave me a discount. They gave me a list of all the codes present and it shows everything but an sbc pump fault code. It does however show the reservoir fault. Also a strange code I am not sure that is related was 5500 critical level at front axle.
The other list of codes the dealer gave me all sbc related were.
C2131
C2534
C223C
C22BC
C2514
C22FB
C2131